Unconnected Body Accrual of Dietary Lipid and Protein in Rats Fed Diets with Different Lipid and Protein Content.

SCOPE Eating large amounts of fat is usually associated with fat accumulation. However, different types of diets (not only lipids) elicit different metabolic responses. METHODS AND RESULTS Male and female rats (10wk-old) were distributed in four groups and fed for one-month a standard diet (SD), or this diet enriched with either lipid (high-fat diet, HF) or protein (high-protein diet, HP), or a cafeteria diet (CAF). Both HF and CAF diets shared the percentage of energy from lipids (40%) but these were different. Protein-derived energy in the HP diet was also 40%. Feeding SD, HF and HP diets did not result in differences in energy intake, energy expenditure, total body weight or lipid content. However, the CAF fed groups showed increases in these parameters, which were more marked in the male rats. The CAF diet increased the mass of adipose tissue while the HF diet did not. CONCLUSIONS Different diets produced substantial changes in the fate of ingested nutrient energy. Dietary lipids were not essential for sustaining increases in body lipid (or adipose tissue) content. Body protein accrual was unrelated to dietary lipids and overall energy intake. Both protein and lipid accrual were more efficient in male than in female rats. This article is protected by copyright. All rights reserved.